MATLAB: Do I get a “Could not find CEL file” warning when attempting to read a CHP file using the AFFYREAD function

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When I attempt to read a CHP file by executing the following code:
affyread('HG-U133A-1-121502.CHP')
I receive the following result:
 Warning: Could not find the CEL file c:\genechip\testdata\arraycd\HG_U133A_replicate_1.CEL.
 No results information will be included in the probe sets.  ERROR: 
 ??? Error using ==> affyread
 Error reading HG-U133A-1-121502.CHP.
I receive this error even though I have the data file, HG-U133A-1-121502.CHP, and the library files, HG-U133A.CDF and HU-U133A.GIN, in the current directory.

Best Answer

This bug has been fixed in Release 2007b (R2007b). For previous product releases, read below for any possible workarounds:
This enhancement has been incorporated in Release 2007a+ (R2007a+). For previous product releases, read below for any possible workarounds:
The CHP file contains summarized data about the chip, but the probe level results are stored in the CEL file. Therefore, the CEL file is needed to be able to work with the probe level data. Also, the CEL file must be available in the directory it was in when the CHP file was created, which in this example is "c:\genechip\testdata\arraycd" directory.
The help documentation will be updated to provide the example with more details on the files needed to read CHP files.
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